TY - JOUR
T1 - A novel lipoprotein-mediated mechanism controlling sexual attractiveness in a colorful songbird
AU - McGraw, Kevin
AU - Parker, Robert S.
N1 - Funding Information:
We thank M. Bacon of Cornell’s Office of Sponsored Programs and D. Owens of Pfizer Inc. for assistance with acquiring atorvastatin, E. Adkins-Regan for use of her finch colonies and input on experimental design, T. van Deusen, D. Sheils, and P. Smith for animal care, V. Johnson at Polymedco Inc. for help with cholesterol assays, E. Mackillop for administering dietary cholesterol, and D. DeNardo, G. Walsberg, and an anonymous referee for helpful comments on the manuscript. KJM was financially supported by a graduate STAR fellowship from the Environmental Protection Agency and by the School of Life Sciences and College of Liberal Arts and Sciences at Arizona State University. All procedures reported here were approved by the Institutional Animal Care and Use Committee at Cornell University (protocol # 99-89).
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2006/1/30
Y1 - 2006/1/30
N2 - Sexually selected traits like complex vocalizations or vibrant colors communicate reliable information about mate quality when they are costly to display. Although several general condition-dependent mechanisms underlying the acquisition of mating advertisements have been identified, we rarely know the precise physiological and molecular challenges that animals must meet to develop their sexual ornaments. The flashy pigment-based colors commonly displayed by birds are ideal candidates for investigating the pathways and demands of sexual-signal expression, because we know the biochemical currency with which the trait is produced. Carotenoid colors in birds, for example, are derived from pigments that are acquired from the diet and assimilated into feathers and bare parts. In previous work, we showed that variation in the sexually attractive red carotenoid-colored beak of male zebra finches (Taeniopygia guttata) was predicted not by the amount of food or pigments ingested, but by the levels of carotenoids that birds circulated in blood. Here we elucidate a novel physiological mechanism by which birds are able to accumulate high levels of carotenoids in the body and develop a colorful bill. Carotenoids are transported through the bloodstream bound to lipoproteins. We assayed a critical component of lipoprotein particles-cholesterol-and found that males with higher cholesterol levels circulated more carotenoids and displayed redder beaks. Experimental supplementation of dietary cholesterol elevated carotenoid levels in the blood and beak hue. Experimental reductions in blood cholesterol, using the human lipid-lowering agent atorvastatin, diminished blood carotenoids and faded the beak; carotenoid and cholesterol levels were restored, however, by subsequent addition of dietary cholesterol. These results suggest that the production of circulating lipoproteins critically regulates the development of a colorful sexually selected trait in zebra finches.
AB - Sexually selected traits like complex vocalizations or vibrant colors communicate reliable information about mate quality when they are costly to display. Although several general condition-dependent mechanisms underlying the acquisition of mating advertisements have been identified, we rarely know the precise physiological and molecular challenges that animals must meet to develop their sexual ornaments. The flashy pigment-based colors commonly displayed by birds are ideal candidates for investigating the pathways and demands of sexual-signal expression, because we know the biochemical currency with which the trait is produced. Carotenoid colors in birds, for example, are derived from pigments that are acquired from the diet and assimilated into feathers and bare parts. In previous work, we showed that variation in the sexually attractive red carotenoid-colored beak of male zebra finches (Taeniopygia guttata) was predicted not by the amount of food or pigments ingested, but by the levels of carotenoids that birds circulated in blood. Here we elucidate a novel physiological mechanism by which birds are able to accumulate high levels of carotenoids in the body and develop a colorful bill. Carotenoids are transported through the bloodstream bound to lipoproteins. We assayed a critical component of lipoprotein particles-cholesterol-and found that males with higher cholesterol levels circulated more carotenoids and displayed redder beaks. Experimental supplementation of dietary cholesterol elevated carotenoid levels in the blood and beak hue. Experimental reductions in blood cholesterol, using the human lipid-lowering agent atorvastatin, diminished blood carotenoids and faded the beak; carotenoid and cholesterol levels were restored, however, by subsequent addition of dietary cholesterol. These results suggest that the production of circulating lipoproteins critically regulates the development of a colorful sexually selected trait in zebra finches.
KW - Carotenoid pigmentation
KW - Ornamental coloration
KW - Sexual selection
KW - Taeniopygia guttata
KW - Zebra finch
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U2 - 10.1016/j.physbeh.2005.09.001
DO - 10.1016/j.physbeh.2005.09.001
M3 - Article
C2 - 16202433
AN - SCOPUS:29144498029
VL - 87
SP - 103
EP - 108
JO - Physiology and Behavior
JF - Physiology and Behavior
SN - 0031-9384
IS - 1
ER -